1. Field of the Invention
The present invention generally relates to computers and software, and more particularly, to security involved in accessing a web resource on a server with a client browser.
2. Description of Related Art
As known in the art, the Internet is a world-wide collection of networks and gateways that use the TCP/IP suite of protocols to communicate with one another. At the heart of the Internet is a backbone of high speed data communication lines between major nodes or host computers consisting of thousands of commercial government educational and other computer systems that route data and messages.
World Wide Web (WWW) refers to the total set of interlinked hypertext documents residing on hypertext transfer protocol (HTTP) servers all around the world. Documents on the WWW, called pages or web pages, are written in hypertext mark-up language (HTML) identified by uniform resource locators (URL) that specify the particular machine and pathname by which a file can be accessed and transmitted from node to node to the end user under HTTP. A web site is a related group of these documents and associated files, scripts, subprocedures, and databases that are served up by an HTTP server on the WWW.
Users need a browser program and an Internet connection to access a web site. Browser programs, also called "web browsers," are client applications that enable a user to navigate the Internet and view HTML documents on the WWW, another network, or the user's computer. Web Browsers also allow users to follow codes called "tags" imbedded in an HTML document, which associate particular words and images in the document with URLs so that a user can access another file that may be half way around the world, at the press of a key or the click of a mouse.
These files may contain text (in a variety of fonts and styles), graphic images, movie files, and sounds as well as java applets, perl applications, other scripted languages, active X-controls, or other small imbedded software programs that execute when the user activates them by clicking on a link. Scripts are applications that are executed by a HTTP server in response to a request by a client user. These scripts are invoked by the HTTP daemon to do a single job, and then they exit.
One type of script is a common gateway interface (CGI) script. Generally, a CGI script is invoked when a user clicks on an element in a web page, such as a link or image. CGI scripts are used to provide interactivity in a Web page. CGI scripts can be written in many languages including C, C++, and Perl. A CGI-BIN is a library of CGI scripts applications that can be executed by a HTTP server.
A key difficulty with access to these documents and associated files, scripts, subprocedures, and databases that are served up by an HTTP server on the WWW is that of security. How does one ensure that only allowed users from allowed client systems are permitted access to the server application and also ensure that access cannot be perverted to malicious purposes?
The method currently being used involves use of a "cookie." Cookies are blocks of data that a server returns to a client in response to a request from the client. The block of data is then stored on a client's system. When the client returns to the same web site, the client sends a copy of the cookie back to the server, thereby identifying the client to the server. Cookies are used to identify users, to instruct the server to send a customized version of the requested web page, to submit account information for the user, and for other administrative purposes. On most systems, a cookie program is run during user logon.
The prior solution for providing security when accessing web resources suffers from the following security weaknesses. It will be shown later how the present invention addresses and overcomes certain of these difficulties.
A problem with the prior solutions is that the host addresses and user names (i.e., user logon information) are sent in plain text that is very open to "spoofing". A knowledgeable hacker can transmit packets pretending to be from another machine or another user to thereby gain unauthorized access to the server.
Yet another problem arises when multiple levels of user security are attempted. The cookie method only allows a single level of security. Moreover, the use of cookies does not allow for a user application to be integrated with a security system. Currently, cookies are part of the client browser program and are separate from a user application.
Another problem in the prior art is that the authentication is weak. This is because the server accepts the user and host name as identified in the transmission without proof. Furthermore, there is a problem in that no state is maintained since each command transaction stands alone. This leaves these methods open to "replay attacks" wherein a hacker captures a valid network packet, alters some details (like the name of the user or the command to execute) and resends it.
However, until now, network systems have lacked the ability to provide flexible and heightened security for web documents on the Internet or other types of networks.